Government Procurement Case and Bid-Winning Solution Analysis for the Dongfeng Yizhan-Series Sewage Treatment Vehicle in Changchun Against the backdrop of increasingly stringent environmental regulations, a municipal sanitation department in Changchun launched a procurement project for Dongfeng Yizhan-series sewage treatment vehicles at the end of 2025. The initiative aims to address the pressure of phasing out older vehicles due to the nationwide full implementation of China VI emission standards, while also resolving operational challenges posed by Northeast China’s severe winter cold. Based on publicly available tender information, this article interprets the core highlights of the winning bid and analyzes how Chengli Special Purpose Vehicle Co., Ltd.’s China VI-compliant solution meets customer requirements. Policy Context of the China VI Transition and Timeline for Phasing Out Older Vehicles According to the Ministry of Ecology and Environment’s ‘Limits and Measurement Methods for Pollutant Emissions from Heavy-Duty Diesel Vehicles (China VI)’, China VIa standards were implemented nationwide starting July 1, 2021; China VIb standards officially took effect on July 1, 2023. This means that in severely cold regions such as Changchun, a large number of sewage treatment vehicles meeting China IV and China V emission standards must be retired and replaced by the end of 2025. The approximate phase-out timeline is as follows: China IV vehicles: largely phased out of the market by the end of 2025; some regions have already implemented early driving restrictions. China V vehicles: beginning in 2026, certain cities will gradually restrict entry into core urban districts; full elimination is expected by 2028. China VIb vehicles: all new vehicle registrations since July 1, 2023 must comply with China VIb standards; these vehicles are projected to dominate the market for the next decade. In response to this policy, the Urban Management Bureau of a district in Changchun explicitly stipulated in its procurement documents that all tendered vehicles must feature Dongfeng chassis, Yizhan-series superstructures, and engines compliant with China VIb emission standards. Additionally, given that winter temperatures in Changchun frequently drop below –20°C, vehicles must incorporate freeze-resistant engine-starting capabilities and low-temperature hydraulic system stability. Chengli’s China VI Solution: Optimized for Winter Operations As a leading enterprise in China’s special-purpose vehicle industry, Chengli Special Purpose Vehicle Co., Ltd. submitted a Yizhan-series sewage treatment vehicle solution based on Dongfeng chassis for this tender. The solution integrates Chengli’s proprietary superstructure, with reference models CLW5070GSSD6 (Dongfeng chassis) and CLW5180GSSD6 (higher-capacity variant). Key specifications are as follows: Item Specification (based on publicly available tender information) Chassis Model Dongfeng D9 series (wheelbase options: 3,950 mm / 4,500 mm) Engine Yuchai YCY30165-60, China VIb-compliant, max. power: 121 kW Superstructure Type Yizhan-style cargo box with hydraulic tilting mechanism; body capacity approx. 8–12 m³ Sewage Treatment System Integrated vacuum pump + filtration tank; treatment capacity approx. 20–30 m³/h Freeze Protection Cold-start assistance system (electrically heated fuel system, ethylene glycol coolant preheating), insulated hydraulic lines Hydraulic System Low-temperature hydraulic oil (rated for –35°C), cold-resistant rubber seals Winter Maintenance Standard-fit antifreeze and low-temperature lubricants; optional engine preheater Regarding low-temperature hydraulic stability, Chengli’s solution employs specially formulated hydraulic oil and cold-resistant seals to ensure normal hydraulic system operation even at –30°C. According to publicly available tender information, this solution has demonstrated...